1. Field of the Invention
The invention relates to an electrical contact coupling for a track-borne vehicle, particularly a railway vehicle.
Electrical contact couplings are usually employed in rail vehicle technology to transmit control signals and power between two neighboring car bodies of a multi-member vehicle. The arrangement, control and size of the electrical contact couplings employed depend on the installation space available in the vehicle and on the number of signals to be transmitted as well as the requirements of the rail car manufacturer and/or the railway operator.
2. The Prior Art
Electrical contact couplings are usually configured such that two electrical contact couplings can be coupled and uncoupled automatically. To that end, the electrical contact couplings arranged on the vehicles or car bodies to be coupled are precisely joined together by means of centering devices and then the sealing surfaces configured on the end faces of the electrical contact couplings pressed together so as to achieve a reliable sealing against the environment. In the uncoupled state, a protective flap covers the end face of the electrical contact coupling in order to protect the coupling elements or any live contact elements of the electrical contact coupling there may be from contact and contamination.
For example, the DE 938 915 A printed publication discloses an electrical contact coupling for railway vehicles to couple electrical lines and signal lines. This electrical contact coupling comprises a coupling housing to be fixed to a car body of a railway vehicle, said housing being designed to accommodate coupling elements or contacts and exhibiting a coupling opening at its end face. The coupling opening can be closed by a protective flap mounted on the housing so as to be pivotable between a closed position and an open position.
In detail, this known prior art solution makes use of a relatively complex mechanism consisting of a plurality of articulated arms and pivot points in order to be able to pivot the protective flap relative to the coupling housing.
In order to simplify the mechanism employed to pivot the protective flap, it is in principle conceivable to connect the protective flap to the coupling housing by means of single-joint hinges such that the protective flap can be pivoted about a fixed axis of rotation. However, using single-joint hinges to pivot the protective flap does have the disadvantage that when the protective flap is in the closed position, the flap contour does not seat completely solidly on the sealing face of the coupling housing, respectively the sealing face of the coupling housing's front frame, and thus neither is an effective sealing usually possible, the main problem thereby being the lateral sealing gaps between the protective flap and the coupling housing. The lateral cracks thus present when the protective flap is in the closed position can allow the infiltration of dust, particularly metallic dust, and moisture, which can lead to reduced surface resistance. Abrasive dirt particles can also infiltrate, causing increased wear on the electrical contacts.
If additional seals are used to seal the lateral sealing gaps between the protective flap and the coupling housing in the closed position of the protective flap, friction acting on the lateral sealing elements cannot be avoided when the protective flap is opened and closed, which leads to increased wear on the lateral sealing elements.